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Effects of KCl concentration on accumulation of acyclic sugar alcohols and trehalose in conidia of three entomopathogenic fungi
Author(s) -
Hallsworth J.E.,
Magan N.
Publication year - 1994
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/j.1472-765x.1994.tb00785.x
Subject(s) - beauveria bassiana , paecilomyces , conidium , trehalose , erythritol , metarhizium anisopliae , bassiana , food science , polyol , water activity , arabitol , sugar alcohol , glycerol , sugar , chemistry , botany , biology , xylitol , biological pest control , organic chemistry , fermentation , water content , geotechnical engineering , engineering , polyurethane
Beauveria bassiana, Metarhizium anisopliae and Paecilomyces farinosus were grown on Sabouraud Dextrose Agar (SDA) modified with KCl to give a range of water activity (a w ) from 0.938 to 0.998. Growth of all three species was optimal at 0.983 a w and growth occurred over the a w range tested. Acyclic sugar alcohol (polyol) and trehalose content of conidia was determined by HPLC and found to vary with species and a w . Conidia of B. bassiana and P. farinosus were found to contain totals of 1.5% and 2.3% polyols respectively at 0.998 a w , and double these amounts at <0.950 a w . Conidia of M. anisopliae contained from 5.7% to 6.8% polyols at each a w tested. In conidia of all three species the predominant polyol was mannitol. The lower molecular weight polyols, arabitol and erythritol, were found to accumulate at reduced a w . Small amounts of glycerol were present in conidia of each species; <15% total polyols. Conidia of B. bassiana and M. anisopliae contained about 0.5% trehalose from 0.970 to 0.998 a w , but only trace amounts below 0.950 a w . Conidia of P. farinosus contained 2.1% trehalose at 0.998 a w and this decreased to <0.1% below 0.950 a w . Potential to manipulate the endogenous reserves of conidia of these biological control agents to enhance viability and desiccation toierance is discussed